A sound reproduction company faces several major concerns in moving a sound system from one venue to the next. From an acoustic standpoint, a movable sound system must produce a desired output level while maintaining high fidelity. The system must also be directionally flexible so that polar sound wave patterns can be varied to suit the acoustical shape of each particular performance location.
From a practical standpoint, other factors that must be considered include the truck space required to pack the system, the number of men required to set up and tear down the system, the weight of the speakers themselves, and the complexity of both connecting the electrical cables to the speakers and suspending or flying the system from the ceiling of an auditorium in a particular orientation. Safety must also be considered in flying a system. Ultimately, the success of a movable sound system depends to a large extent upon its ability to adequately address each of these concerns in a cost effective manner.
Some prior sound systems have utilized a modular approach to address some of these concerns. For instance, O'Neill et al. U.S. Pat. No. 4,805,730 discloses a loudspeaker enclosure having trapezoidal shaped end (top and bottom) walls, a back wall and two side walls extending between the end walls. Each of the side walls has outwardly projecting ribs that extend on a line between a front wall and the rear wall. One side wall has an odd number of ribs while the other side wall has an even number of ribs. Placing of two of these enclosures side by side intermeshes the outwardly projecting ribs. By inserting a pivot pin through aligned holes in the intermeshed ribs, the enclosure can be secured together at a fixed angular relationship that is determined by the shapes of the end wall trapezoids. While the ribs facilitate side by side connection of these enclosures, the overall versatility of this system is rather limited due to the fact that the angular relationship between adjacent speakers is predetermined and fixed by the shapes of the end walls. Moreover, the side wall ribs do not provide any benefit in vertical stacking of the enclosures.
LeTourneau U.S. Pat. No. 4,179,008 also shows a modular approach. A group of cylindrically shaped speaker housings with interspaced angled wedge blocks are held taut in a generally toroidal shape by a flexible tension member. The tension member is releasable so that the speaker housings can be rotated into a selective orientation. Subsequently, the tension member is tightened to retain the speakers in the selected orientation. This system provides some directional versatility in that each of the speaker housings may be rotated. However, the versatility of the system is also rather limited because a predetermined number of housings and wedges are required to complete the toroidal shape. Again, as with O'Neill, the system does not provide any advantage in vertically stacking the housing. Moreover, the wedges also represent an additional shipping cost.
Griffin U.S. Pat. No. 4,014,597 discloses two main speaker enclosures that can be latched together to form a box to facilitate transporting of the speakers. The internal configurations of the enclosures are dimensioned to receive and hold two auxiliary speakers. The enclosures have handles mounted to their external surfaces to further facilitate transport. While this speaker enclosure may facilitate transport, the rearwardly converging side walls make it difficult to hang two of these enclosures in side-by-side relationship.
In view of the shortcomings in these and other prior art sound systems, there exists a need to develop a sound system that can be quickly and easily adapted to accommodate the acoustic parameters of a wide variety of performance venues, and which can be packed, shipped, electrically connected and hung in a cost effective manner.